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Technologies to Target Circadian Rhythm Disruption in PTSD



OBJECTIVE: To develop and demonstrate a wearable device that can monitor circadian rhythm cycles, determine daytime napping and provide a deterrent to the latter. This device will continuously collect physiological signals, and integrate them in order to estimate circadian rhythm. There may be a companion light modulation component to alter the portion of the light spectrum that regulates the circadian rhythm. The entire package will utilize a smart device which can enable health professionals to carry out further evaluations and repair the disrupted cycle.

DESCRIPTION: Terrestrial species have adapted to the Earth’s 24-hour pattern of daylight and darkness by evolving biological rhythms, called circadian rhythms, which repeat at approximately 24-hour intervals. For humans, circadian rhythms are regulated and generated by a master clock located in the suprachiasmatic nuclei (SCN) in the hypothalamus in the brain. Lack of synchrony between the master clock in SCN and the external environment, referred to as circadian misalignment, can lead to circadian disruption, with potential detrimental consequences ranging from increased sleepiness and decreased attention span during the day, lower productivity, gastrointestinal disorders, to long-term health problems such as increased risk for cancer, diabetes, obesity, and cardiovascular disorders. Some of these problems are closely associated with Post traumatic stress disorder (PTSD). At issue for PTSD in Service members is an increase in daytime napping, with the resultant inability to obtain a deep REM sleep (a restful necessity) at night. The insomnia and resultant exhaustion, likely contribute to many of the key issues seen in PTSD (metabolic syndrome, anger, etc.). Circadian rhythm reset is not likely to solve all aspects of PTSD, but could restore this key pathway which has far-reaching involvement with the HPA axis, metabolism, etc. A safe method to solicited to diminish napping, and provide other therapies (such as light adjustments, etc.) as well as to enable health professionals to determine more specific aspects of the circadian disruption. The ideal system will undoubtedly have multiple components, but be relatively user-friendly. Clinical trials using PTSD cases may be possible to test the successful device when it has been optimized. COTS devices currently exist for wearable devices that monitor activity, galvanic skin responses, temperature and other physiologic conditions which are useful especially for PTSD cases. Those devices would supply collected data to a smart device to integrate information and define circadian status. Other COTS devices such as Philips light panel that provides blue light to affect circadian rhythm, offer alternatives for effective regulation of circadian rhythm and avoidance of circadian misalignment. Detection of daytime napping and a strategy to interfere in that process is not currently available. The integration of the various aspects cited would have potential to be an aid in reversal of one of the debilitating aspects of PTSD. The goal of this STTR topic is to leverage the large body of research literature on circadian rhythm and couple it to the advance in wearable/embedded device technologies to develop an integrated circadian rhythm regulation device.

PHASE I: Given the short duration of Phase I, this phase should not encompass any human use testing that would require formal IRB approval. Phase I should focus on system design for rapid realignment of circadian rhythm to the external environment and to develop a strategy for detection and disruption of daytime napping. At the end of this phase, a working prototype of the device(s) and the application(s) should be completed and some demonstration of feasibility, integration, and/or operation of the prototype. In addition, descriptions of data syncing concept, interoperability concerns, and data storage and tracking should be outlined. Phase I should also include the detailed development of Phase II testing plan.

PHASE II: During this phase, the integrated system should undergo human subject testing for evaluation of the operation and effectiveness of utilizing an integrated system and its capability to aid the PTSD cases to avoid daytime napping and achieve real-world outcomes of circadian rhythm regulation, sleep, and alertness. Accuracy, reliability, and usability should be assessed. This testing should be controlled, rigorous. Statistical power should be adequate to document initial efficacy, feasibility and safety of the device. This phase should also demonstrate evidence of commercial viability of the tool. Accompanying the application should be standard protocols and procedures for its use and integration into ongoing programs. These protocols should be presented in multimedia format.

PHASE III DUAL USE APPLICATIONS: The ultimate goal of this topic is to develop and demonstrate a wearable device that can be utilized as a personal circadian rhythm regulation device by synthesizing physiological signals into a circadian rhythm estimate and adjusting circadian light input based on the estimate. This device should also seamlessly integrate with other peripheral device(s), web-based and Smartphone applications, and provide additional feedback and monitoring tools for long term health assessment. The final system will be integrated into other Army informational systems such as ArmyFit and AHLTA. In addition the system may be marketed to commercial consumers for improving general health of shift workers.


    • Zhang J., Wen, J.T., Julius, A., “Optimal circadian rhythm control with light input for rapid entrainment and improved vigilance,” 51st IEEE Conference on Decision and Control (CDC), pp. 3007--3012, Dec. 10-13, 2012


    • Smith, M. R., & Eastman, C. I. (2012). Shift work: health, performance and safety problems, traditional countermeasures, and innovative management strategies to reduce circadian misalignment. Nature, 4, 111-132.


  • Mott C., Dumont G., Boivin, D.B., and Mollicone, D. Model-based human circadian phase estimation using a particle filter. IEEE Transactions on Biomedical Engineering, 58(5):1325– 1336, 2011.

KEYWORDS: Health, Circadian Rhythm, Wearable Device, Technology, Military Health, Activity, Sleep, Alertness

  • TPOC-1: Dr. Marti Jett
  • Phone: 301-619-2029
  • Email:
  • TPOC-2: Dr Virginia Pasour
  • Phone: 919-549-4375
  • Email:
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